The Stratigraphy and Foraminiferal Fauna of the Santa Susana Formation
<p>The Santa Susana formation on the north side of the Simi Valley, Ventura County, California consists of 2360 feet of marine sediments. Macro-fossils found by previous workers indicate that the formation represents the the Meganos Eocene. As these fossils came from the upper 300 feet of the...
| Summary: | <p>The Santa Susana formation on the north side of the Simi Valley, Ventura County, California consists of 2360 feet of marine sediments. Macro-fossils found by previous workers indicate that the formation represents the the Meganos Eocene. As these fossils came from the upper 300 feet of the formation, nothing was known concerning the correlation of the remainder of the section.</p>
<p>Abundant and well preserved foraminifera have been found by the writer through the entire section, with the exception of the lower 275 feet. These micro-fossils indicate that the lower portion of the Santa Susana is also of Meganos age.</p>
<p>The fauna has been found to consist of three distinct faunules which form the basis for the same number of zones. The validity of this zoning must be tested by checking the present section with others in this and other localities. This has not as yet been possible.</p>
<p>The foraminifera indicate that the Santa Susana formation represents two stages of the Gulf Coast Eocene succession, the upper Midway and the overlying Wilcox. Approximately fifty per cent of the total species present in the lower two zones are present in the upper Midway of Texas. The correlation of the upper zone with the Wilcox of Alabama is less certain.</p>
<p>Six lithologic members are present in the section which show that the beds became gradually finer from the basal conglomerate upward into the middle shale member and then becomes coarser from the top of the shale member upward. These lithologic members do not correspond with the faunal divisions.</p> |
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